rpart.pca {mvpart}R Documentation

Principle Components Plot of a Multivariate Rpart Object

Description

Plots a PCA of the rpart object on the current graphics device.

Usage

## S3 method for class 'pca':
rpart(tree, pts = TRUE, plt.allx = TRUE, speclab = TRUE,
    specvecs = TRUE, wgt.ave = FALSE, add.tree = TRUE,  
    cv1 = 1, cv2 = 2, chulls = TRUE, interact = FALSE, ...) 

Arguments

tree A fitted object of class rpart containing a multivariate regression tree.
pts If TRUE, large points representing the leaf means are plotted.
plt.allx If TRUE, small points representing individual cases are plotted.
speclab If TRUE the labels of the response variables are plotted.
specvecs If TRUE the vectors of the response variables are plotted provided wgt.ave is FALSE .
wgt.ave If TRUE use weighted averages of responses not vectors.
add.tree If TRUE add the tree structure to the plot.
cv1 Defines the principal component to plot horizontally – but see interact.
cv2 Defines the principal component to plot vertically – but see interact.
chulls If TRUE adds convex hulls to thr tree groups.
interact If TRUE the plot can be viewed in dimensions by left-clicking to top-left, bottom-right or bottom-left (reset).
... arguments to be passed to or from other methods.

Details

This function plots a PCA biplot of the group means (leaves) of multivariate regresssion objects of class rpart. The responses and group means and indivdual cases can be shown on the plot. If responses are positive (eg species-environment data) weighted averages of responses can be plotted.

Value

NULL

Side Effects

A PCA biplot plot is produced on the current graphics device.

See Also

rpart, text.rpart

Examples

data(spider)
fit<-mvpart(data.matrix(spider[,1:12])~herbs+reft+moss+sand+twigs+water,spider)
rpart.pca(fit)
rpart.pca(fit,wgt.ave=TRUE,interact=TRUE)

[Package mvpart version 1.2-6 Index]